An important goal in plant community ecology is to understand how species traits determine demographic performance and consequently shape distribution patterns. Effect of topography on plant performance may be pronounced in mountain tropical forests with dry season. We examined the associations among species traits, demography and topographic variation where species occur for 98 co-occurring species in the 15 ha forest dynamics plot in a tropical mountain forest, Thailand. We hypothesized that species with acquisitive traits often occur in the ridge and show faster growth rates compared to conservative species. We examined leaf traits (leaf mass per area, thickness, toughness, leaf dry matter content, nitrogen content), maximum size, and diameter relative growth rates (RGR) of species, and then applied multivariate statistics to evaluate trait-topography relationships. First axis of trait syndrome was positively associated with RGR and leaf nitrogen content and negatively associated with leaf toughness supporting the leaf economical spectrum from acquisitive to conservative. First axis of environmental gradients was positively associated with elevation, slope and index of convex, indicating the environment close to the ridge. Our results indicate that species with higher nitrogen content and higher relative growth rate tend to occur in the environment close to the ridge with higher elevation, stepper slope and index of convex.